An apparatus for determining crystallization solidification curves of a fat-containing mass is known from German Patent No. DE 37 14 951 C1 corresponding to U.S. Pat. No. 4,889,434. The known apparatus includes a measurement chamber being surrounded by a cooled wall. The measurement chamber is connected to a removal location (for example a tube section) for liquid pre-crystallized chocolate from which the liquid sample of chocolate is removed. The measurement chamber partly protrudes into the cross-section of flow of the tube. The measurement chamber has a cylindrical cross-section, and it is thus coordinated with a cylindrical piston being arranged in the measurement chamber to be movable in the measurement chamber. The piston carries a temperature sensor which protrudes beyond the front wall of the piston. In its retracted position, the piston protrudes into the measurement chamber to observe and sense the temperature of the solidified sample at this position. The measurement chamber is thus formed by a piston and cylinder unit which is arranged to immerse into the chocolate mass to be observed with its open front side. A drive serves to provide the stroke of the piston, the stroke being approximately coordinated with the length of the measurement chamber. A unit for removal of the solidified sample from the piston and from the temperature sensor is provided. This unit includes a mechanical crushing apparatus, especially a milling unit or a cutting unit the axis of which is aligned with the axis of the measurement chamber. The milling or cutting unit includes a shaft and a milling head driven by a motor. The milling head protrudes into the cross-section of flow of the measurement chamber from outside, and it partly locks the cross-section of flow. The shaft has to be sealed.
The known apparatus is operated as follows: Liquid chocolate mass is sucked in from the removal location and transferred into the measurement chamber by a backward stroke of the piston in the measurement chamber. The liquid sample solidifies due to the influence of the cooled wall of the measurement chamber until the entire material of the sample has solidified. To be capable of sucking in the following sample of liquid chocolate mass into the measurement chamber, the solidified sample has to be removed from the measurement chamber. This is realized by the mechanical crushing apparatus with which the solidified sample is milled. The solid particles resulting therefrom are introduced into the liquid chocolate mass which flows through the removal location. In the following, these particles are further conveyed and melted in the flow. The crushing and melting process of the solidified sample takes several minutes. The measurement chamber cannot be used during this time, meaning it is not possible to transfer another sample into the measurement chamber. Instead, one has to wait until the entire crushing and melting process of the solidified sample has been completed. Then, another sample can be taken. The period of time for checking a sample is comparatively long such that it is only possible to take samples in respective time intervals. However, a control system often requires quicker processing of samples.
The known apparatus also has the drawback of the mechanical crushing apparatus requiring its own drive. This separate drive is located outside of the removal location, and it includes rotatingly driven elements. Consequently, the milling head of the mechanical crushing apparatus, for example, it not accessible for maintenance and controlling purposes since it is located inside of the removal location. Furthermore, a seal is required for the arrangement of the drive shaft to protrude through the wall of the removal location. Furthermore, a conduit or a tube section is required. The seal is a wearing part, and it needs to be regularly replaced to prevent the chocolate mass from exiting in an undesired way.
Another drawback of the known apparatus is that it is necessary to control the drive for the piston in the measurement chamber and for the mechanical crushing apparatus in an exact way. The forward stroke of the piston with the solidified sample may not be completed before the crushing apparatus has milled the solidified sample.